Relative biological effectiveness (RBE), quality factor (Q) and radiation weighting factor (wR) * Editor: J. Valentin, Published by: ICRP Publication 92, Annals of the ICRP, Vol: 33(4), 117 pp (2003)

2004 ◽  
Vol 108 (3) ◽  
pp. 270-271
Author(s):  
D. M. Taylor
Keyword(s):  
Quality Factor ◽  
Relative Biological Effectiveness ◽  
Weighting Factor ◽  
Biological Effectiveness ◽  
Quality Factor Q ◽  
Icrp Publication

scholarly journals High-Accuracy Relative Biological Effectiveness Values Following Low-Dose Thermal Neutron Exposures Support Bimodal Quality Factor Response with Neutron Energy

2022 ◽  
Vol 23 (2) ◽  
pp. 878
Author(s):  
Laura C. Paterson ◽  
Amy Festarini ◽  
Marilyne Stuart ◽  
Fawaz Ali ◽  
Christie Costello ◽  
...  
Keyword(s):  
Dna Damage ◽  
Thermal Neutron ◽  
Quality Factor ◽  
Neutron Energy ◽  
Relative Biological Effectiveness ◽  
High Energy ◽  
Weighting Factor ◽  
Radiological Protection ◽  
Thermal Neutrons ◽  
Biological Effectiveness

Theoretical evaluations indicate the radiation weighting factor for thermal neutrons differs from the current International Commission on Radiological Protection (ICRP) recommended value of 2.5, which has radiation protection implications for high-energy radiotherapy, inside spacecraft, on the lunar or Martian surface, and in nuclear reactor workplaces. We examined the relative biological effectiveness (RBE) of DNA damage generated by thermal neutrons compared to gamma radiation. Whole blood was irradiated by 64 meV thermal neutrons from the National Research Universal reactor. DNA damage and erroneous DNA double-strand break repair was evaluated by dicentric chromosome assay (DCA) and cytokinesis-block micronucleus (CBMN) assay with low doses ranging 6–85 mGy. Linear dose responses were observed. Significant DNA aberration clustering was found indicative of high ionizing density radiation. When the dose contribution of both the 14N(n,p)14C and 1H(n,γ)2H capture reactions were considered, the DCA and the CBMN assays generated similar maximum RBE values of 11.3 ± 1.6 and 9.0 ± 1.1, respectively. Consequently, thermal neutron RBE is approximately four times higher than the current ICRP radiation weighting factor value of 2.5. This lends support to bimodal peaks in the quality factor for RBE neutron energy response, underlining the importance of radiological protection against thermal neutron exposures.

The Question of Relative Biological Effectiveness and Quality Factor for Auger Emitters Incorporated into Proliferating Mammalian Cells

1991 ◽  
Vol 128 (3) ◽  
pp. 282 ◽  
Author(s):  
Roger W. Howell ◽  
Dandamudi V. Rao ◽  
De-Yan Hou ◽  
Venkat R. Narra ◽  
Kandula S. R. Sastry
Keyword(s):  
Quality Factor ◽  
Mammalian Cells ◽  
Relative Biological Effectiveness ◽  
Biological Effectiveness

scholarly journals Neutron relative biological effectiveness in Hiroshima and Nagasaki atomic bomb survivors: a critical review

2016 ◽  
Vol 57 (6) ◽  
pp. 583-595 ◽  
Author(s):  
Masao S. Sasaki ◽  
Satoru Endo ◽  
Masaharu Hoshi ◽  
Taisei Nomura
Keyword(s):  
Cancer Risk ◽  
Radiation Exposure ◽  
Atomic Bomb ◽  
Relative Biological Effectiveness ◽  
Weighting Factor ◽  
Atomic Bomb Survivors ◽  
Biological Effectiveness ◽  
Γ Rays ◽  
Neutron Component ◽  
Risk Of Cancer

Abstract The calculated risk of cancer in humans due to radiation exposure is based primarily on long-term follow-up studies, e.g. the life-span study (LSS) on atomic bomb (A-bomb) survivors in Hiroshima and Nagasaki. Since A-bomb radiation consists of a mixture of γ-rays and neutrons, it is essential that the relative biological effectiveness (RBE) of neutrons is adequately evaluated if a study is to serve as a reference for cancer risk. However, the relatively small neutron component hampered the direct estimation of RBE in LSS data. To circumvent this problem, several strategies have been attempted, including dose-independent constant RBE, dose-dependent variable RBE, and dependence on the degrees of dominance of intermingled γ-rays. By surveying the available literature, we tested the chromosomal RBE of neutrons as the biological endpoint for its equivalence to the microdosimetric quantities obtained using a tissue-equivalent proportional counter (TEPC) in various neutron fields. The radiation weighting factor, or quality factor, Qn, of neutrons as expressed in terms of the energy dependence of the maximum RBE, RBEm, was consistent with that predicted by the TEPC data, indicating that the chromosomally measured RBE was independent of the magnitude of coexisting γ-rays. The obtained neutron RBE, which varied with neutron dose, was confirmed to be the most adequate RBE system in terms of agreement with the cancer incidence in A-bomb survivors, using chromosome aberrations as surrogate markers. With this RBE system, the cancer risk in A-bomb survivors as expressed in unit dose of reference radiation is equally compatible with Hiroshima and Nagasaki cities, and may be potentially applicable in other cases of human radiation exposure.

NÉEL LINES STRUCTURES IN UNIAXIAL FERROMAGNETS WITH QUALITY FACTOR Q > 1

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-1947-C8-1948
Author(s):  
J. Miltat ◽  
P. Trouilloud
Keyword(s):  
Quality Factor ◽  
Quality Factor Q

scholarly journals 422 Million intrinsic quality factor planar integrated all-waveguide resonator with sub-MHz linewidth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew W. Puckett ◽  
Kaikai Liu ◽  
Nitesh Chauhan ◽  
Qiancheng Zhao ◽  
Naijun Jin ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Capacity ◽  
Precision Spectroscopy ◽  
Narrow Linewidth ◽  
Waveguide Resonator ◽  
Environmental Disturbances ◽  
Fiber Communications ◽  
Intrinsic Quality ◽  
Quality Factor Q ◽  
Quantum Photonics

AbstractHigh quality-factor (Q) optical resonators are a key component for ultra-narrow linewidth lasers, frequency stabilization, precision spectroscopy and quantum applications. Integration in a photonic waveguide platform is key to reducing cost, size, power and sensitivity to environmental disturbances. However, to date, the Q of all-waveguide resonators has been relegated to below 260 Million. Here, we report a Si3N4 resonator with 422 Million intrinsic and 3.4 Billion absorption-limited Qs. The resonator has 453 kHz intrinsic, 906 kHz loaded, and 57 kHz absorption-limited linewidths and the corresponding 0.060 dB m−1 loss is the lowest reported to date for waveguides with deposited oxide upper cladding. These results are achieved through a careful reduction of scattering and absorption losses that we simulate, quantify and correlate to measurements. This advancement in waveguide resonator technology paves the way to all-waveguide Billion Q cavities for applications including nonlinear optics, atomic clocks, quantum photonics and high-capacity fiber communications.

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